Chitin and Chitosan derivatives are a family of biopolymers containing N-acetyl-D-glucosamine and D-glucosamine subunits. Chitin is widely found in the exoskeletons of arthropods, shells of crustaceans, and the cuticles of insects while chitosan is mostly produced in industry by alkaline hydrolysis of chitin. Both chitin and chitosan are promising polymers for a variety of applications. The biomedical applications of chitin and chitosan are of particular interest because of their biocompatibility, biodegradability and structural similarity to the glycosaminoglycans. Their medical and biomedical applications and potential applications include dressings for wound-healing, tissue engineering applications, artificial kidney membranes, drug delivery systems, absorbable sutures, hemostats, antimicrobial applications, as well as applications in dentistry, orthopedics, ophthalmology, and plastic surgery. Despite these potential applications of chitin and chitosan, few chitin or chitosan products are practically in commercial use. Actually, there appears to be no commercially available chitosan based stents currently on the market even though there are reports of chitosan based stents, for example, as disclosed in U.S. Pat. No. 8,414,925.
In the process of developing chitosan based biodegradable stents, it's surprisingly found that using the conventional polytetrafluoroethylene (PTFE) coated guidewires to deliver these chitosan based stents into a body lumen of a subject is extremely difficult, or impossible due to the fact that these chitosan based stents would buckle, re-coil, or not be in a proper position during the delivering process. As a result, there is a practical need for methods and systems for properly delivering these chitosan based stents into a body lumen of a subject in order to utilize the benefits and advantages of the chitosan and chitin based products as indicated in previous paragraph.